Hydrologic modeling of runoff from a livestock manure windrow composting site with a fly ash pad surface and vegetative filter strip buffers

Abstract

Windrow composting of livestock manure materials provides a strategy for converting organic wastes into a recyclable soil fertility product that is less hazardous to the environment. Although outdoor windrow composting can produce runoff that is detrimental to surface water quality, vegetative filter strip (VFS) buffers were reported to significantly reduce runoff and contaminants from a windrow composting research site. To estimate the efficacy of VFS buffers and other best management practices on runoff from future windrow composting facilities, a computer hydrologic model may provide a valuable tool for predicting runoff losses from these proposed sites. This research evaluated a windrow composting/vegetative filter strip buffer (WCVFS) hydrologic model for estimating runoff volume losses from a livestock manure-based windrow composting site with a fly ash composting pad surface and VFS buffers. Runoff and physical attribute data from six rainfall events during 2002 to 2004 at a central Iowa windrow composting research site were used in the WCVFS model evaluation. Three rainfall events were designated as "wet" composting period events (2002 and 2003 seasons), and three were designated as "dry" composting period events (2004 season). Runoff data were comprised of average observed runoff volumes from three compost windrow area:VFS buffer area ratio treatments that included 1:1, 1:0.5 (large and small VFS buffer areas, respectively), and a 1:0 (no buffer) control. The WCVFS model performance was good to very good for the 2003 wet composting period model validation rainfall event with no significant differences among 1:1, 1:0.5, and 1:0 ratio treatments for simulated versus observed runoff volumes. In contrast, WCVFS model performance was unsatisfactory for the 2004 dry composting period validation event with significantly higher simulated runoff volume from the 1:0.5 ratio treatment versus observed runoff volumes. There were no significant differences for the 1:1 and 1:0 treatments. The WCVFS model effectively estimated 1:1, 1:0.5, and 1:0 treatment runoff volumes from the earlier wet composting period and 1:1 and 1:0 treatment runoff volumes from the later dry composting period rainfall events. However, the soils data-derived VFS buffer runoff and infiltration functions in the WCVFS model flow routing component may not have sufficiently accounted for some short-term hydrologic changes in VFS buffer soil and fly ash pad surfaces. This could have resulted in overestimation of dry composting period simulated runoff volume from the smaller 1:0.5 ratio VFS buffer area treatment. Consequently, the use of other alternatives to soils data-derived VFS buffer runoff and infiltration functions should be evaluated in future WCVFS model simulation trials to potentially improve runoff volume prediction accuracy. Abstract: Windrow composting of livestock manure materials provides a strategy for converting organic wastes into a recyclable soil fertility product that is less hazardous to the environment. Although outd...

Inorganic nitrogen losses from irrigated maize fields with narrow buffer strips

“…Although extensive research has been conducted on BS in recent years (Webber et al 2010;Dunn et al 2011;Larson and Safferman 2012;Wang et al 2012), there is still a need to clarify some controversial points. First, it is well known that BS width may be positively correlated to N removal effectiveness.…”

Assessing Surface Flowpath Interception by Vegetative Buffers Using ArcGIS Hydrologic Modeling and Geospatial Analysis for Rock Creek Watershed in Central Iowa

“…Several studies assessing the effectiveness of VFS in intercepting and treating surface runoff have shown that the efficacy of this BMP is influenced by several factors, including the VFS length and width (Wenger, 1999;Zreig et al, 2004), the ratio of runoff source area to VFS area (Dosskey et al, 2011), the VFS buffer species (Ree, 1949;Broadmeadow and Nisbet, 2004), VFS nutrient and sediment trapping (Meyer et al, 1995;Van Dijk et al, 1996;Gharabhaghi et al, 2001;Zreig, 2001;Lee et al, 2003;Webber et al, 2010aWebber et al, , 2010b, VFS performance (Dosskey et al, 2007), concentrated surface flow (Dosskey et al, 2002), and chemical and nutrient concentrations in runoff (Arora et al, 1996(Arora et al, , 2003Boyd et al, 2003;Webber et al, 2009).…”